Exemplary embodiments pertain to the art of rotary wing aircraft and, more particularly, to a variable ratio gearbox for a rotary wing aircraft.
Rotary wing aircraft typically include a main rotor assembly and a tail rotor assembly. The main rotor assembly may provide desired lift while the tail rotor assembly may provide orientation control (yaw) and/or forward propulsion. Typically one or more prime movers, often in the form of internal combustion engines, provide power that drives the main rotor assembly and the tail rotor assembly. A gearbox mechanically links the one or more prime movers with the main rotor assembly and the tail rotor assembly. Currently, the tail rotor assembly is driven at a fixed ratio relative to the main rotor speed.